Process, method, and system for removing mercury from fluids

摘要

Trace amount levels of non-volatile mercury in crude oil are reduced by contacting the crude oil with a water stream containing at least a monatomic water-soluble sulfur species such as sulfides and hydrosulfides. The non-volatile mercury is extracted into the water phase forming a mercury rich wastewater, yielding a treated crude oil having at less than 50% of the original non-volatile mercury level. The wastewater can disposed or recycled by injection into a reservoir. In one embodiment, the water stream consists essentially of produced water.

主权项

1. A method for removing a trace amount of mercury in a crude oil feed, comprising:
providing a crude oil having a first concentration of mercury in which at least 50% of the mercury is non-volatile mercury; mixing into the crude oil an effective amount of a water stream consisting essentially of at least a water-soluble monatomic sulfur compound selected from the group of sodium hydrosulfide, potassium hydrosulfide, ammonium hydrosulfide, sodium sulfide, potassium sulfide, calcium sulfide, magnesium sulfide, and ammonium sulfide and combinations thereof forming a mixture; extracting at least a portion of the non-volatile mercury from the crude oil into water as soluble mercury sulfur complexes forming a mercury rich wastewater; and separating the wastewater containing the soluble mercury sulfur complexes from the crude oil for a treated crude oil having a reduced concentration of non-volatile mercury.